Facebook’s Ugly Little Secret

Facebook has an ugly little secret, a number disclosed nowhere in its voluminous filings to become a public company and now only vaguely addressed by corporate officials.

An estimated 5.6 million Facebook clients — about 3.5 percent of its U.S. users — are children who the company says are banned from the site.

Facebook and many other websites bar people under age 13 because the Children’s Online Privacy Protection Act (COPPA) requires websites to give special treatment to children 12 or younger. The law aims to stop marketers prying personal information from children or using their data to advertise to them. Sites must get parental permission before allowing children to enter, and must take steps to protect privacy.

Facebook declines to acknowledge that many of its efforts to block children are not working.

The issue has taken on new relevance as the Federal Trade Commission finalizes rules to further restrict companies and websites that target youths or are geared to young audiences.

Facebook, the world’s leading social media company with 955 million users, has said that the law does not apply to it because it explicitly restricts use of its site to people aged 13 and older.